This project explicates the development of personal and social competence over the life span of a large sample of mentally retarded individuals as a function of environmental, demographic and personal influences. This is accomplished by a) establishing growth curves for the development of adaptive behavior and vocational competence controlling environmental, demographic and personal influences, b) examining residual variance in terms of modified physical characteristics of placements, and mandated additional educational programming. Additional goals are a) studying the trends in placement and mortality of the mentally retarded as way of evaluating new legislative and licensing requirements, b) investigating the adjustment of retarded individuals and their families to losses of eligibility or access to various programs, c) study of the construct and predictive validity of adaptive behavior and its relationship to other constructs (e.g., affective behavior and mental age) and its ability to predict adjustment outcomes in the community. The sample to be studied consists of the residents of four institutions for the retarded (n equals 4550) and the clients of a community regional center serving the retarded ( N equals 4500). A wide variety of instruments and analytical techniques will be employed.